Machine for straightening and cutting metal wire or strip into pieces

ABSTRACT

A machine for straightening and cutting material in the form of metal wire or strip into lengths comprising a straightening device, a conveyor for conveying the material through the machine and a shearing device for cutting off lengths of the material. In this machine a measured length sensor for measuring the lengths of the material conveyed through the machine and an adjustable required length transmitter for controlling the length of material to be cut off are both connected to a comparison circuit which, as soon as the length sensed by the measured length sensor is equal to that to which the required length transmitter is adjusted brings the material to a standstill and operates the shearing device to cut off a length of the material. The machine is also provided with adjustable number-of-cuts counter which, after each cut has been made resets the measured length sensor and thus causes the cycle of operations of the machine to be repeated until the number of cuts to which the number-of-cuts counter is adjusted is reached.

[ Sept. 11, 1973 Unite States Patent [1 Ritter et al.

3,429,163 2/1969 Munchbach 72/131 MACHINE FOR STRAIGHTENING AND CUTTINGMETAL WIRE OR STRIP INTO PIECES Primary ExaminerMilton S. MehrAttorney-Ernest F. Marmoek [75] Inventors: Klaus Ritter; Hans Giitt;Gottfried Zechner; Gerhard Ritter, all of Graz, Austria [57] ABSTRACT Amachine for straightening and cutting material in the form of metal wireor strip into lengths comprising a straightening device, a conveyor forconveying the material through the machine and a shearing device forcutting off lengths of the material. In this machine a measured lengthsensor for measuring the lengths of the material conveyed through themachine and an adjustable required length transmitter for controllingthe length of material to be cut off are both connected to a comparisoncircuit which, as soon as the length U S Cl 72/l2 72,17 72/l31 sensed bythe measured length sensor is equal to that to which the required lengthtransmitter is adjusted brings the material to a standstill and operatesthe shearing device to cut off a length of the material. The machine isalso provided with adjustable number-0fcuts counter which, after eachout has been made resets 83/69 BZlf 11/00 l References Cited themeasured length sensor and thus causes the cycle UNITED STATES PATENTSof operations of the machine to be repeated until the number of cuts towhich the number-of-cuts counter is adjusted is reached.

3,199,391 8/1965 Haner et al. 83/69 3,439,517 4/1969 Munchbach 72/15 X3,640,164 2/1972 Crafford et al. 83/69 X 6 Claims, 4 Drawing FiguresPatented Sept. 11, 1973 3,757,552

4 Sheets-Sheet 1 FIG.|

Patented Sept. 11, 1973 3,757,552

4 Sheets-Sheet 2 Patented Sept. 11, 1973 4 Sheets-Sheet 5 Paiented Sept.11, 1973 3,757,552

4 Sheets-Sheet 1L 42 42a [in W1 [WI [m HTI [LII [11] LL LL11 LLQ rm m rm[[1] W 50a 5|a MACHINE FOR STRAIGIITENING AND CUTTING METAL WIRE ORSTRIP INTO PIECES Conventional machines for straightening and cuttingmetal wire or strip into lengths usually have at least one set ofstraightening rollers through which the metal wire or strip, which willsubsequently be called the material"is conveyed by a conveyor. In thosecases where the material is of a section which has essentially the samemoment of inertia in all directions perpendicular to its longitudinalaxis, for example in the case of circular wire, two or more sets ofstraightening rollers are required, and the straightening planes ofthese sets intersect. On the other hand in those cases in which thesection of the material has greatly different moments of inertia in twodirections perpendicular to its longitudinal axis and at right angles toeach other, it is usually sufficient to provide a single set ofstraightening rollers, the straightening plane of which is perpendicularto the direction of the smaller moment of inertia of the section.

In addition to straightening the material it is necessary to be able tocut it off into lengths. For this purpose the conventional machines areprovided, downstream of the straightening rollers, with mechanical stopswhich are adjustable in position longitudinally. When the leading end ofthe travelling material comes into contact with the mechanical stop,this brings the conveyor to a standstill and if desired automaticallyoperates a shearing device.

A machine of this kind is described for example in the applicantsAustrian Patent Specification No. 237,410. However this conventionalmeans for stopping the conveyor and for operating the shearing devicewith the aid of mechanical stops is not suitable for use in theproduction of comparatively small batches of material of particularlength. A machine of this conventional kind is not capable, under thesecircumstances, of operating rapidly enough and reliably enough, becauseeach time the cut-off length is changed the mechanical stop has to bereadjusted in position and locked in place. This resetting of themachine often takes longer than the straightening and cutting offoperation itself.

The object of the present invention is to provide a machine forstraightening and cutting metal wire or metal strip into lengths, themachine being free from the disadvantages mentioned above and theadjustment necessary for cutting different lengths being able to beeasily and rapidly effected.

According to this invention, in a machine for straightening and cuttingmaterial in the form of metal wire or strip into lengths, the machinecomprising a straightening device, a conveyor for conveying the materialthrough the machine and a shearing device for cutting off lengths of thematerial, a measured length sensor for measuring the length of thematerial conveyed through the machine and an adjustable required lengthtransmitter for controlling the length of material to be cut off, areboth connected to a comparison circuit which, as soon as the lengthsensed by the measured length sensor is equal to that to which therequired length transmitter is adjusted, brings the material to astandstill and operates the shearing device which cuts off a length ofthe material, the machine also being provided with an adjustablenumber-of-cuts counter which, after each cut has been made, resets themeasured length sensor, causing the cycle of operations to be repeateduntil the number of cuts to which the number-of-cuts counter is adjustedis reached.

Preferably, the machine further comprises a programming system includinga number of independent required length transmitters and an equal numberof independent number-of-cuts counters, the individual transmitter andcounter pairs, each pair consisting of one required length transmitterand one number-ofcuts counter, being arranged to be energised one afterthe other, the programming system being arranged in such a way that assoon as the number of cuts made reaches that to which one number-of-cutscounter is adjusted, this counter and the transmitter in the pair aredisconnected and the next pair are energised.

This form of the invention makes it possible to programme a productionrun in which a whole series of batches of different lengths arestraightened and cut, each batch containing a required number of piecesall of the same length, the lengths being, however, different in thedifferent batches.

Once the machine has been started it goes through the entire programmeautomatically without any further attention by the operator. It may pullthe material off a storage reel and it then straightens and cuts,entirely automatically, the required series of batches of cut-offmaterial the batches having different lengths from each other.

An example of a machine constructed in accordance with the invention isillustrated somewhat diagrammatically in the accompanying drawings, inwhich:

FIG. 1 is a front view of the machine;

FIG. 2 is a front view of further parts of the machine shown in FIG. 1,these parts not being visible in FIG. 1 because they are situated behindthe front of the machine;

FIG. 3 is a circuit diagram'of the control system of the machine; and,

FIG. 4 is a circuit diagram of a programming system for the machine.

As shown in FIG. 1, the material which is to be straightened and cut offinto lengths advances through the machine in the direction of an arrow Palong a horizontal path A-A. The material is conveyed by a conveyorformed by two pairs of motor-driven driving rollers 1, 2. The lower pairof driving rollers 2 can be raised and lowered, relative to the upperpair 1. When the machine is operating the lower pair of rollers 2 isthrust upwards towards the upper pair I by a thrust spring 3,

so that the material is clamped firmly between the'two pairs of drivingrollers, a drive being applied to the material by friction. The spring 3is mounted on a sliding pull rod 5. At its lower end the spring 3thrusts against a guide plate 4 fixed to a frame of the machine. Theupper end of the spring 3 thrusts against a cross beam 6 to which theupper end of the rod 5 is fixed.

The rod 5 slides up and down in a hole through the guide plate 4,raising and lowering the cross beam 6. Bearings 20 for the two drivingrollers 2 are fixed to the two ends of the cross beam 6, the arrangementallowing the lower pair of driving rollers 2 to be adjusted in positionvertically.

As shown in FIG. 2, the two pairs of driving rollers l and 2 are drivenby an electric motor 11. Worms 13 and 14 are keyed to a driving shaft 12of the motor and these worms mesh with the:worm wheels 15, 16. One wormwheel 15 is coaxial with and fixed to one of the upper driving rollers land the other worm wheel 16 is coaxial with and fixed to one of thelower driving rollers 2. The other two driving rollers are driventhrough V-belts l7 and 18.

The mechanism for raising and lowering the lower pair of driving rollers2 is arranged as follows. The lower end of the rod is pivotally attachedto a lever 7, which is itself pivotally mounted at one end 8 on theframe of the machine. The other end of the lever 7 is pivotallyconnected to the lower end of a piston rod 9 the piston of which slidesin a pivotally mounted pneumatic cylinder 10. Compressed air supplied tothe cylinder 10 moves the piston rod 9 downwards, rocking the lever 7about its pivoted end 8 so that the sliding rod 5 is moved downwardsagainst the action of the spring 3. This lowers the lower pair ofdriving rollers 2 away from the upper pair 1, releasing the material sothat it ceases to be driven. The material is therefore brought to astandstill.

Just upstream of the driving rollers l, 2 there is a straighteningdevice 20. Lower rollers 2i of this device are rotatably mounted inbearings fixed to the frame of the machine. Upper rollers 22, on theother hand, are adjustable in position vertically. The bearings of theupper straightening rollers 22 are connected to a lever 23 pivoted atone end 24 to the frame of the machine. An eccentric 25 acts on theother end of the lever 23, to rock this lever up or down about itspivoted end 24. This arrangement allows the upper straightening rollers22 to be adjusted in position vertically relative to the lowerstraightening rollers 21.

The system for cutting the material into lengths is arranged as follows:the electric motor 11 drives a flywheel 27 through a V-belt 26. Theflywheel 27 is coupled by a pneumatic coupling 28 to an eccentric 29,which is merely indicated in FIGS. 1 and 2 of the drawings. Theeccentric 29 drives a connecting rod 30 which actuates a shearing device31.

An electro-pneumatic valve 32 (H6. 1), controlled as will be describedlater, controls the admission of compressed air to the cylinder 10, forlowering the lower pair of driving rollers 2 and also controls theengagement of the coupling 28 for actuating the shears 3i.

Downstream of the two pairs of driving rollers 1 and 2 there is ameasured length sensor 35 which senses the advancing movement of thematerial. The sensor 35 has a measuring wheel 36 mounted on an arm whichis pivoted about a vertical axis 37. A spring, not shown, thrusts themeasuring wheel 36 against the surface of the travelling material sothat the measuring wheel is rotated by the moving material. As indicatedin FIG. 3, the measuring wheel 36 drives a pulse transmitter disc 38a.The rim of the disc 38a moves between the arms of a pulse transmitterfork 38. The rim of the disc 38a can for example have slots or teeth.The pulse transmitter fork 38 can be constructed, for example, as aphotoelectric or a magnetic sensor.

The number of pulses sent out by the pulse transmitter fork 38 isproportional to the distance of advance of the material. The pulses fromthe pulse transmitter fork 38 are transmitted to a pulse divider 39. Themode of operation of the pulse divider 39 is as follows: let it beassumed that the material is to be cut off into lengths each of which isa whole number of centimetres and that the tolerated error in length is0.25 cm. Under these circumstances the pulse transmitter fork 38 whichforms a measured length transmitter, must deliver four pulses for eachcentimetre of advance. The pulse divider 39 divides the pulses in theratio 4 l. The pulses delivered by the pulse transmitter fork 38 to thepulse divider 39 are therefore accurate within the tolerated 0.25 cm,four pulses being delivered for each 1 cm of advance of the material.The pulses delivered by the pulse divider 39 represent the specifieddistance of advance in centimetres.

The pulses delivered by the pulse divider 39 are transmitted to a pulsecounter 40 which is connected to a comparison circuit 41 which is itselfconnected to a required length transmitter 42 which is adjustable. Theadjustment of the required length transmitter 42 determines the lengthof the cut-off piece of material. The arrangement functions as follows.As soon as the material -has advanced the desired distance,corresponding to the setting to which the required length transmitter 42has been adjusted, the comparison circuit 41 delivers a signal, througha conductor 43, a cut counter 44 and a power stage 45, to a cutcommander 46, which can for example take the form of an energising coilof the electro-pneumatic valve 32. On receiving this signal the cutcommander 46 by sending a com mand to the compressed air cylinder 10,brings the material to a standstill and also, engaging the pneumaticcoupling 28, operates the shears 31, cutting the material. The cutcounter 44 also delivers, through a feedback conductor 47, a resettingsignal to the pulse counter 40, starting a further operational cycle inwhich the material is advanced through a further measured distance. Thecut counter 44 is connected to a number-of-cuts transmitter 48, which isadjustable by the operator. By adjusting the number-ofcuts transmitter48 the operator determines the number of cut-off lengths of material hewishes the machine to produce in a given batch, the length of each pieceof material being determined by the setting of the required lengthtransmitter 42. That is to say, the number-of-cuts transmitter 48determines the number of pieces cut, whereas the required lengthtransmitter 42 determines the length of each piece. During the operationof the machine the pulse counter 40 is repeatedly reset by theconsecutive cut counter 44, which counts the cuts made, the cycles beingrepeated until the number of cuts preset on the number-of-cutstransmitter 48 is reached, whereupon the electric motor 11 is switchedoff, for example through a conductor 49 and/or the lower pair of drivingrollers 2 is lowered, bringing the travelling material to a standstill.

In the preferred example of the invention a programming system as shownin FIG. 4 is provided. The programming system contains a number ofrequired length transmitters 42 which can be individually 'preset to therequired cut-off lengths, and an equal number of number-of-cutstransmitters 48 which can be individually preset to the required numberof pieces in each batch. All the required length transmitters 42 areconnected in common through individual relay switches 50 to thecomparison circuit 41. Similarly all the number-of-cuts transmitters 48are connected in common through indi vidual relay switches 51 to the cutcounter 44. Each controlling pair of transmitters consisting of arequired length transmitter 42 and a number-of-cuts transmitter 48, isconnected by simultaneous closing of the relevant switches 50 and 51 inthe programming system. In the example shown the required lengthtransmitter 42a is connected through the switch 50a to the comparisoncircuit 41 and the number-of-cuts transmitter 48a is connected throughthe switch 51a to the cut counter 44.

The programming system functions as follows: when the machine is inoperation, the material travels forwards along the path AA and as soonas the comparison circuit 41 detects that the distance travelled isequal to the required length, the comparison circuit 41 delivers a pulsethrough the conductor 43 to the consecutive cut counter 44, which stopsthe advance of the material and energises the cut commander 46,actuating the shearing device 31 and cutting the material. The cycle isrepeated, successive lengths of material being cut until thenumber-of-cuts transmitter 48 detects that the required number oflengths of material have been cut for the batch, whereupon a commandsignal is delivered, for example through the conductor 49, which closesthe next relay switch in the chain of consecutively actuated switches.Thus the two controlling transmitters 42 and 48 are disconnected and adifferent pair of controlling transmitters are connected for the cuttingof a further batch of material, the cycle being repeated until theentire programme of batches has been cut.

The required length transmitter, the measured length sensor, thenumber-of-cuts transmitter and the cut counter can for example be in theform of four-pole mechanical switches of the kind which have a countingfunction, particularly pulse controlled step switches. However insteadof mechanical switches, electronic switches are preferably used, forexample in the form of chain counters or the like.

The example described can be modified in various ways, for example twoor more straightening devices can if desired be arranged to operate inparallel with each other, the straightening devices both feeding to acommon shearing device. All the straightening devices are thencontrolled by a common measuring and controlling system, the whole beingarranged so that material from two or more production lines issimultaneously cut into lengths.

We claim:

1. In a machine for straightening and cutting material in the form ofmetal wire or strip into lengths, said machine comprising astraightening device, a conveyor for conveying the material through themachine and a shearing device for cutting off lengths of the material,the improvement comprising measured length sensing means for measuringthe length of the material conveyed through the machine, an adjustablerequired length transmitting means for controlling the length ofmaterial to be cut off, means connecting said length sensing means andsaid transmitting means to a comparison circuit and means operativelyconnecting said comparison circuit to said shearing device and saidconveyor whereby as soon as the length sensed by said length sensingmeans is equal to that to which said transmitting means is adjusted,said conveyor is operated to bring said material to a standstill andsaid shearing device is operated to cut off a length of said materialand further comprising adjustable number-of cuts counter means and meansconnecting said number of cuts counter means to said sensing meanswhereby after each cut has been made said sensing means is reset and thecycle of operations of said machine is repeated until the number of cutsmade by said shearing device is equal to that to which saidnumber-of-cuts counter means is adjusted.

2. A machine as claimed in claim 1, further comprising a programmingsystem including a plurality of independent length transmitting means,an equal plurality of independent number-of-cuts counting means andmeans for energising one of said plurality of length transmitting meansand said counting means successively whereby as soon as the number ofcuts made by said shearing device reaches that to which said one of saidnumber-of-cuts counting means is adjusted this counting means and theassociated length transmitting means are disconnected and the nextsuccessive length transmitting means and number-of-cuts counting meansare energised.

3. A machine as claimed in claim 1, wherein said length sensing meansincludes a pulse transmittor, a measuring roller, means for rotatingsaid measuring roller by said material as said material is conveyed bysaid conveyor and means driving the connecting said roller to saidpulsetransmittor, said pulse transmittor including a toothed disc and aphoto-electric or magnetic pulse transmittor cooperating with saidtoothed disc whereby said disc delivers electric pulses proportional innumber to the length of material conveyed by said conveyor and saiddelivered pulses are transmitted to pulse counting means connected tosaid comparison circuit.

4. In a machine for straightening and cutting material in the form ofmetal wire or strip into lengths, said machine comprising astraightening device, a conveyor for conveying the material through themachine and a shearing device for cutting off lengths of the material,the improvement comprising measured length sensing means for the lengthof the material conveyed through the machine, an adjustable requiredlength transmitting means for controlling the length of material to becut off, means connecting said length sensing means and saidtransmitting means to a comparison circuit and means operativelyconnecting said comparison circuit to said shearing device and saidconveyor whereby as soon as the length sensed by said length sensingmeans is equal to that to which said transmitting means is adjusted,said conveyor is operated to bring said material to a standstill andsaid shearing device is operated to cut off a length of said materialand further comprising adjustable number-of-cuts counter means and meansconnecting said number of cuts counter means to said sensing meanswhereby after each cut has been made said sensing means is reset and thecycle of operation of said machine is repeated until the number of cutsmade by said shearing device is equal to that to which saidnumber-of-cuts counter means is adjusted, said conveyor includes drivingrollers, means for rotating said driving rollers and means for movingsaid driving rollers towards and away from said material, said means formoving said driving rollers including a pneumatic device and a pneumaticcontrol circuit controlling said device, said pneumatic control circuitincluding an electro-pneumatic valve and means connecting said valve tosaid comparison circuit for control thereby, a pneumatic couplingoperatively connected to said shearing device and means operativelyconnecting said valve to said pneumatic coupling.

5. A machine as claimed in claim 4, further compris ing a supportsupporting said driving rollers, a spring acting upon said support, arod connected to said superate in parallel with each other, saidplurality of straightening devices feeding said shearing device and saidstraightening devices being controlled by said comparison circuit.

1. In a machine for straightening and cutting material in the form ofmetal wire or strip into lengths, said machine comprising astraightening device, a conveyor for conveying the material through themachine and a shearing device for cutting off lengths of the material,the improvement comprising measured length sensing means for measuringthe length of the material conveyed through the machine, an adjustablerequired length transmitting means for controlling the length ofmaterial to be cut off, means connecting said length sensing means andsaid transmitting means to a comparison circuit and means operativelyconnecting said comparison circuit to said shearing device and saidconveyor whereby as soon as the length sensed by said length sensingmeans is equal to that to which said transmitting means is adjusted,said conveyor is operated to bring said material to a standstill andsaid shearing device is operated to cut off a length of said materialand further comprising adjustable number-of cuts counter means and meansconnecting said number of cuts counter means to said sensing meanswhereby after each cut has been made said sensing means is reset and thecycle of operations of said machine is repeated until the number of cutsmade by said shearing device is equal to that to which saidnumber-of-cuts counter means is adjusted.
 2. A machine as claimed inclaim 1, further comprising a programming system including a pluralityof independent length transmitting means, an equal plurality ofindependent number-of-cuts counting means and means for energising oneof said plurality of length transmitting means and said counting meanssuccessively whereby as soon as the number of cuts made by said shearingdevice reaches that to which said one of said number-of-cuts countingmeans is adjusted this counting means and the associated lengthtransmitting means are disconnected and the next successive lengthtransmitting means and number-of-cuts counting means are energised.
 3. Amachine as claimed in claim 1, wherein said length sensing meansincludes a pulse transmittor, a measuring roller, means for rotatingsaid measuring roller by said material as said material is conveyed bysaid conveyor and means driving the connecting said roller to said pulsetransmIttor, said pulse transmittor including a toothed disc and aphoto-electric or magnetic pulse transmittor cooperating with saidtoothed disc whereby said disc delivers electric pulses proportional innumber to the length of material conveyed by said conveyor and saiddelivered pulses are transmitted to pulse counting means connected tosaid comparison circuit.
 4. In a machine for straightening and cuttingmaterial in the form of metal wire or strip into lengths, said machinecomprising a straightening device, a conveyor for conveying the materialthrough the machine and a shearing device for cutting off lengths of thematerial, the improvement comprising measured length sensing means forthe length of the material conveyed through the machine, an adjustablerequired length transmitting means for controlling the length ofmaterial to be cut off, means connecting said length sensing means andsaid transmitting means to a comparison circuit and means operativelyconnecting said comparison circuit to said shearing device and saidconveyor whereby as soon as the length sensed by said length sensingmeans is equal to that to which said transmitting means is adjusted,said conveyor is operated to bring said material to a standstill andsaid shearing device is operated to cut off a length of said materialand further comprising adjustable number-of-cuts counter means and meansconnecting said number of cuts counter means to said sensing meanswhereby after each cut has been made said sensing means is reset and thecycle of operation of said machine is repeated until the number of cutsmade by said shearing device is equal to that to which saidnumber-of-cuts counter means is adjusted, said conveyor includes drivingrollers, means for rotating said driving rollers and means for movingsaid driving rollers towards and away from said material, said means formoving said driving rollers including a pneumatic device and a pneumaticcontrol circuit controlling said device, said pneumatic control circuitincluding an electro-pneumatic valve and means connecting said valve tosaid comparison circuit for control thereby, a pneumatic couplingoperatively connected to said shearing device and means operativelyconnecting said valve to said pneumatic coupling.
 5. A machine asclaimed in claim 4, further comprising a support supporting said drivingrollers, a spring acting upon said support, a rod connected to saidsupport and a pivoted lever connected to said rod and to said pneumaticdevice whereby when said pneumatic device is operated, said support islowered against the action of said spring.
 6. A machine as claimed inclaim 1, further comprising a plurality of straightening devicesarranged to operate in parallel with each other, said plurality ofstraightening devices feeding said shearing device and saidstraightening devices being controlled by said comparison circuit.